Chapter 15. Troubleshooting Procedures and Best Practices

OBJECTIVES

This chapter covers the following CompTIA-specified objectives for the “Network Support” section of the Network+ exam:

Given a network problem scenario, select an appropriate course of action based on a general troubleshooting strategy. This strategy includes the following steps.

• Establish the symptoms

• Identify the affected areas

• Establish what has changed

• Select the most probable cause

• Implement a solution

• Test the results

• Recognize the potential effects of the solution

• Document the solution

• In order for troubleshooting to be successful, it must be approached in a structured manner. These steps describe a troubleshooting methodology that has been proven in the field.

Given a troubleshooting scenario involving a network with a particular physical topology (i.e. bus, star/hierarchical, mesh, ring, and wireless) and including a network diagram, identify the network area affected and the cause of the problem.

• Physical topology problems are infrequent, but they do occur. You will need to be able to identify the symptoms of a topology error and the steps necessary to correct them.

Given a network troubleshooting scenario involving a client connectivity problem (e.g. incorrect protocol/client, software/authentication configuration, or insufficient rights/permissions), identify the cause of the problem.

• Client connectivity problems are common. The fact that users are involved in the troubleshooting process adds an interesting twist. Communication skills are often as important as technical skills in the solution of a problem.

Given a network troubleshooting scenario involving a wiring/infrastructure problem, identify the cause of the problem (e.g. bad media, interference, network hardware).

• Although wiring is resilient to failure, it can and does become faulty. It can also be affected by outside sources, which can create some challenges for troubleshooters. In addition, the devices used to create networks can fail, which often renders entire sections of a network, or the whole network, unusable.

OUTLINE

Introduction

Troubleshooting Basics

Troubleshooting Servers and Workstations

General Troubleshooting Considerations

The Art of Troubleshooting

Establishing What the Symptoms Are

Information from the Computer

Information from the User

Observation Techniques

Effective Questioning Techniques

Identifying the Affected Area

Establishing What Has Changed

Changes to the Network

Changes to the Server

Changes to the Workstation

Selecting the Most Probable Cause of the Problem

Implementing a Solution

Testing the Results

Recognizing the Potential Effects of the Solution

Documenting the Solution

Troubleshooting Topology Errors

Bus Network Errors

Star Network Errors

Ring Network Errors

Mesh Network Errors

Wireless Network Errors

Troubleshooting Client Connectivity Errors

Protocol Errors

Protocol-Specific Issues

Authentication

Permissions Errors

Physical Connectivity Errors

Troubleshooting Wiring- and Infrastructure-Related Problems

Troubleshooting Wiring

Determining Your Wiring

Where the Cable Is Used

Troubleshooting the Infrastructure

Baselines and Performance Monitoring

Troubleshooting Checklists

Troubleshooting Cable Problems

Troubleshooting Network Connectivity

Troubleshooting Network Printing

Troubleshooting Data Access

Troubleshooting NICs

Chapter Summary

Apply Your Knowledge

STUDY STRATEFIES

• Read the objectives at the beginning of the chapter.

• Study the information in the chapter, paying special attention to the tables that summarize key information.

• Review the objectives again.

• Pay close attention to the “Troubleshooting Scenario and Solution” sidebars. They focus on specific areas of knowledge for the Network+ exam.

• Answer the exam questions at the end of the chapter and check your results.

• Use the ExamGear test on the CD-ROM that accompanies this book to answer additional exam questions concerning this material.

• Review the notes, tips, and exam tips in this chapter. Make sure you understand the information in the exam tips. If you don't understand the topic referenced in an exam tip, refer to the information in the chapter text and then read the exam tip again.